First off all we have an extremely big problem with radical Islam in the world. If we look at polls from Africa and the middle east, a clear majority of muslims support Sharia law. About 30-50% support either ISIS, Al-shabab, Boko Haram or Al-qaida. It is not safe to bring in people to your country that may have certain values that are unacceptable in our western countries. Especially not values that supports death penalty for homosexuals, stoning for adultery, oppression of womens liberties etc.
And just look at our European countries (i'm from Sweden), look at new years eve in Germany, where over a thousand muslims gathered and starting to rape and physically harass young German women/girls. Thousands! Not one or two, thousands! ISIS have also admitted that they have sent thousands of their warriors into Europe, disguising as refugees. You must either be blind or refuse to see the threat that we are dealing with. Or you may just be a middle-class person living far away from heavily immigrated areas where neither you or your family are affected by the crime or intolerance that these people bring with them.

And the argument that we just have to let them come into our countries because "they are dying" is ridiculous. It is not our responsibility to help these people. It's the neighbors of Syria who should help them. It's absurd to assume that a person has to travel to another part of the world in order to so call "survive". Honestly the people who are actually escaping, escapes to countries nearby such as Turkey or Lebanon. People who want to come to Germany or Sweden, only wants so to grab our welfare money.
We don't help anyone by letting them exploit us.